I've decided I'd like to hit the trail right smack in the winter, no later than February 1st. NoBo. I don't mind the cold and the solitude. Methinks comfort is important, but safety is crucial.

With the exception of a 0 Degree Bag: WM Kodiac MF, I don't have a gear list sorted out yet.

Shelter? I know there ought to be shelter space aplenty, but aren't they like iceboxes in the winter? I think I need to get my winter shelter sorted out and my base weight first, yeah?

I've been looking over the Hilleburgs, BDs, etc., and for the amount of space and the price(s) of winter solo or two-person tents, I'm not liking the choices. I am 6' tall and know that a tight fit is not going to cut it, that is, at least not a tent wall in my face all night. I have an EV2, but this isn't suitable.

If I were you, I'd opt for an MLD Duomid (cuben, if you can swing it) and enjoy the bug-free conditions with a lot of weight-savings. It works great in the type of snowfall you can expect hiking north in February, and you can either stake it completely to the ground (it feels like a completely enclosed shelter) or lift it a bit for ventilation based on your needs and the conditions. Should you still want to use it deeper into spring, you could easily combine an inner net for total double-walled protection.

I did about 3.5 months on the AT starting in December and ending mid March. I also routinely go winter camping, as it is by far my prefered season.

To answer your question specifically:
Shelter. Yes Shelters/leantos on the AT are generally a little colder than just sleeping on the ground due to the shelters normally being lifted off the ground. Using the shelters is easily doable if you have a good pad setup. You do still need to bring some kind of shelter in case you can't make it to the next shelter. Depending on your budget this can be a real whallop to your budget. You want a freestanding tent for winter preferably, as tieing dead men etc for days on end really gets old. I used a TNF Mountain 25 for me and my brother on our trip, and nowadays I use a hammock and tarp. Whatever shelter option you do choose make sure to practice setting it up in the snow, and with mittens on(kinda simulate numb hands). There is far less daylight hours during the winter, so whatever shelter setup you go with be prepared to spend alot more time in it. So make sure you have some room to move, and make sure it can stand up to some unexpected winter weather.
If you like the ease of using shelters I would recommend just bringing a good bivy as a backup, and you can also use it in the shelter which will help a bit with the cold nature of shelters.

This is what I bring for winter specific gear on my trips:
-Superfly tarp and bivy, or Superfly tarp and hammock
I recommend having several types of stakes, snow stakes and a few nail style to pound into frozen ground along with extra cordage to make deadmen.
-MSR XGK EX stove, and a 22oz bottle of fuel-This will easily last me a 7-12 days if not longer(depending on how much i have to melt snow) using it for cooking 2x a day and a few hot drinks, and melting snow for water.
-Thermarest prolite 4, and a regular ccf pad. or a -5F underquilt and a 1/8 ccf pad if using hammock
– -10F sleeping bag or a -5F quilt if using hammock
-Kahtoola Microspikes always, and sometimes MSR Denali Ascent snowshoes depending on conditions

I do a fair amount of winter hiking in the Southern Appalachians, and love it. February 1st isn't all that early a start anymore for a thru-hike. There are hikers starting in January. The trail won't be crowded, but you won't be alone all the time, either.

Be prepared for some very cold nights — single digit temps (F) — and expect lows in the teens and highs in the 30s and 40s for the most part. You'll likely get a couple of decent snowstorms, too, depending on the year.

Some random thoughts:

The Ex-lite down jacket is nice, but I would freeze my buns off in it that time of year. I'd want a real down jacket, maybe the Alpine Light parka at minimum. I wear an old Sierra Downs down jacket in winter. Weighs 24 ounces, but it's toasty.

I have used my Tarptent Moment in pretty cold weather, and it's worked okay. Plenty of room, but it ventilates well, which means of course that it can be kinda cold. The wind pretty much blows right through. In winter I often sleep in the shelters, and use a winter pad under my bag and a homemade bivy made from Momentum .90 fabric. Not sure what I would do for a thru under those conditions. Might just take my bivy and a good tarp.

I'm comfortable from single digits to mid-70s with this clothing list. (Okay, when it's single digits I am in my WM Antelope bag, but still….)

You'll want a good stove, of course, since you'll need a lot of hot calories. You can easily resupply every 4-5 days on the AT, which means getting into town to a grocery store. Most of the trail towns have a decent store these days. You might find this series of articles on Whiteblaze useful for resupply:

I have a copy of the AT Guide, which I've been studying. Also halfway through Dave Miller's memoir which provides a nice account of where resupply stops, etc. are as well.

Yes, I need to look at down parkas. I have a Mountain Hardware Conduit SL, but, unfortunately, back when I bought it, I was quite a bit heavier and got an XL. Nowadays, I'm swimming in it. Needless to say, it is bulky and heavy, but oh so warm.

By the way, I am considering the Stevenson DAM 60 sleep pad. I like the width. I always find myself off the narrower 20" pads and on the floor much of the time.

good call on the bag :) with your warm layers if needed, you'll be fine well below 0

good call on the Duomid as well, it's my shelter for two, for one it's nice and roomy- ditch the inner when the bugs are gone (but add a ground cloth)

for packs you'll want something large-ish due to the high volume bits your carrying- ULA Circuit should probably do it, also look at the Golite Pinnacle, lot of room for the weight (72 liters ~ 2 #)- it's frameless, but you can add a HPDE frame or such if need be

shoe wise if your going to be in a fair bit of snow/wet/cold a thin wool sock w/ Gore-tex over sock might be worth investigating, really cold and a pair of overshoes might be in order

I recently received a pair (actually two- one for my wife) of goosefeet down booties/overshoes- very nice and very light- for their low weight and little volume I think they might be most welcome

That's hikin. Feb in the Southeast is cold wet n steep but magical at times. Hard to explain why I like it so much. Good advice so far…I'd add that you should have good traction for wet and slippery roots and rocks. Soft rubber. And I've become a fan of neoprene socks. A little disagreement with Mike…the goretex ones will get wet down here anyway by sweat and all of the water you'll cross (the trail is a creek due to erosion), so forget dry feet and just keep your dogs warm. Put your shoes and socks in a plastic bag at the bottom of your bag if you hate putting cold shoes on in the morning. I'll completely agree with Mike on the down booties, though. Generally over do it on the insulation bc it'll deflate with the humidity and carry plenty 'o sleep pad especially if you will be in shelters. You'll be walking in clouds a lot of the time.

You'll meet some characters and people from all over the world out there that time of year. "Ya I did not know the southern states vus dis cold, ya?" Pack lot's o calories and don't leave TP everywhere like the April hikers do.

I would like to hear more from those that are more experienced than I in true winter conditions about your choice of hiking footwear. Back in the 70's I did sections of the AT in winter using leather boots that I treated with SnowSeal. And more often than not, my feet froze. But since my conversion to much lighter weight gear, I hike in trailrunners but have not hiked in snow or true winter conditions so I don't know what to use.

Frank, I really love my Rab Infinity. It weighs 14.6 oz for a men's medium and is by far the warmest parka I've worn. I am using a stripped down Evernew Appalachian stove these days and really enjoy it.

I started the AT NOBO in late Feb last year (2010), and most or all of the advice I've seen here thus far really seems right on to me.

Well, I could quibble with the tent. I started with a Gatewood Cape as both backup shelter (I did indeed sleep in shelters almost the entire trail) and as rain gear, but as the south was hammered pretty hard by more snow than usual in 2010, there were lots of blowdowns, so I swapped for my Contrail (having your only rain gear and shelter shredded by blowdowns isn't a great survival strategy). And it turned out that I virtually never used the contrail, very seldom at any rate. My hiking partner Lucky was ultimately smarter with his SMD Wild Oasis — a lighter backup shelter to carry and very rarely use. I guess bottom line is that the more confident you are that you can always make it to a shelter at night, the more you can balance risk/reward in carrying a lighter (not four season) tent or tarp. YMMV, don't haunt me if you get killed this way … ;-)
Seriously, a well pitched tarp could be a great choice for a person with the right gear to mostly sleep warm in shelters.

I used a MB Ex Light down jacket for the entire CDT this year, again in a pretty tough winter year, and I was fine with that. On the AT with an early Feb start, however, I too would want something warmer; I think there were few if any nights on the CDT this year as cold as I was in late Feb and early March at times on the AT. But I also used a WM 20F bag on both trails, so having a warmer down parka on the AT was not just for general "in camp" use, but also a truly essential part of my sleep system. As were my down booties on the AT at the start (didn't use them on the CDT this year).

I made due for padding with a regular size Neo-air plus a couple of thinlight pads, and this combo worked for me down into the upper teens, but likely not so well much lower. It was nice, however, to have a multi-piece system here where I could mail home thinlite pads as it warmed up; the same approach worked great on the CDT this year too, starting with two thinlites and ending up eventually with none.

One thing about a warmer parka is that mine (MB Alpine lite) was just flat too warm to ever wear hiking, whereas my Ex Lite this year was something I did wear hiking on occasion. On the AT I used a combination of MB thermawrap vest plus windshirt to walk in when cold, removing the vest if/when I warmed up enough, and the vest of course could layer under the parka (not a huge gain in warmth there over the parka, but at low temps you take what you can get!). In terms of clothing to hike in, btw, make sure you're prepared not only for cold temps but for cold wind. Think ear protection (I personally like earbags to augment a couple of hat alternatives), and *mittens* — not gloves. I'm a big fan of Dachstein mittens now, with some sort of light (I used eVent) shell mittens.

I liked using breathable trail runners throughout on all trails, using at times goretex or VB socks, but mostly just wool socks. Differing opinions on this, some very experienced folks prefer a boot when it's very cold out. I personally like wearing shoes that work well for my feet at pretty much all times ("boots: just say no").

I echo the sentiments of whoever recommended Kahtoola microspikes. I'm not sure if the topic of snowshoes came up here, but with an early Feb start it seems to me that it's possible you could find yourself needing those in places, or perhaps having to do a roadwalk or blue blaze route to get around deep snow or perhaps to flip. Tough to know ahead of time. Early starters in 2010 mostly or all did a (also partially snowy) roadwalk from Clingman's Dome to Newfound Gap due to butt-deep snow there that no one had busted through yet, but that was the only time I would have wanted snowshoes with a late Feb start that year.

It's pretty cool being out ahead of most of the pack; the folks that were out at that time were pretty cool too; i.e., one of the benefits was that apart from easy shelter space and just generally fewer people out there, I really enjoyed the company of the folks that were out; I think there was a bit of a special bond there.

I have not tried the microspikes so take this with a grain of salt but they sound like a good idea. One thing that seems to be unique to the east is freezing rain. I haven't seen it in a couple of years (in VA) but it might be more common up high. This stuff can get really nasty when it starts coating rocks and trails. For whatever reason I've never encountered it out west.

It's getting near that time. I did get the Kahtoola MICROspikes. I am considering ditching the snowshoes though and just taking it real easy in the deep stuff if and when…I've good boots and a pair of OR Cascade gaiters.

I'm still trying out a WM Flight. It's light, but I am not loving it. Short and there there seems to be less and less down as you get to the waist. I have a GoLite Bitterroot on the way. I'm going to try that before I commit. I don't want to freeze my tuckus off around camp. Of course there probably won't be a lot of down time before hitting the bag for a good night's rest.